package com.hy.myapp.util;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

/**
 * 用于Rest服务的工具类
 * 
 * @author heyang 2021年10月31日
 */
public class RestUtil {
	/**
	 * 从HttpServletRequest中取得访问者IP
	 * 
	 * @param request
	 * @return
	 */
	public static String findVisitorIpFrom(HttpServletRequest request) {
		String ipAddress = null;
		try {
			ipAddress = request.getHeader("x-forwarded-for");

			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("Proxy-Client-IP");
			}

			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("WL-Proxy-Client-IP");
			}

			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getRemoteAddr();
				if (ipAddress.equals("127.0.0.1")) {
					// 根据网卡取本机配置的IP
					InetAddress inet = null;
					try {
						inet = InetAddress.getLocalHost();
					} catch (UnknownHostException e) {
						e.printStackTrace();
					}
					ipAddress = inet.getHostAddress();
				}
			}

			// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
			if (ipAddress != null && ipAddress.length() > 15) {
				if (ipAddress.indexOf(",") > 0) {
					ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
				}
			}
		} catch (Exception e) {
			ipAddress = "";
		}

		return ipAddress;
	}
}
